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Hybrid
Hybrid network architecture, as shown in Figure 9, as the name would imply, is a combination of
peer-to-peer and client-server types. Except for the smallest of networks, there is rarely a pure
P2P or client-server network, and functionally, all networks offer hybrid service models,
depending on needed services. A single node can use services from a server on the network
while participating with a peer in a distributed file system also on the network and serving
information to a client, all on the same network.
Functionally, network architecture is more than a system of connections among nodes. Modern
computing demands have advanced rapidly, and networks require the centralized control of a
client-service architecture for some demands, but also need the flexibility of open P2P
relationships for other demands.
Cloud-based

In a traditional “on-premise” model, the organization is responsible for all aspects of the network,
including owning and maintaining all servers, storage, operating systems, developing, and
maintaining applications. Cloud-based services offer an alternative to this model.

According to National Institute of Standards and Technology (NIST), “cloud computing is a model
for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable
computing resources (e.g., networks, servers, storage, applications, and services) that can be
rapidly provisioned and released with minimal management effort or service provider interaction”
1
through the internet.
In this model, an organization engages a third-party provider to offer cloud-based services. A
cloud-based architecture can combine or simplify some of the network relationships and offers
flexibility for the cloud service recipient.

There are three general cloud service types in which the service type may be referred to as “’X’
as a service,” abbreviated XaaS. XaaS means "delivery or anything as a service: products,
services, and technologies." The three general cloud service types include Infrastructure (IaaS),
Platform (PaaS), or Software (SaaS). Details on each of these models, compared with the
traditional on-premise model include:
 On-premise – the organization is responsible for all aspects of the network, including
maintaining all servers, storage, operating systems, and developing and maintaining
applications.
 Infrastructure as a Service (IaaS) – the organization owns the maintenance of servers
within the cloud. This is a pay-as-you-go model for network, servers, storage, applications,
etc., where the size can be modified on an as-needed basis. The recipient organization is
responsible for all logical configurations and maintenance, though they typically do not have
access to the hardware. Organizations that desire their own features and functionalities often
use IaaS to develop customized applications without the necessity of housing the
infrastructure. In this case, the IaaS provider, such as Amazon Web Services (AWS),

1. Peter Mell, Tim Grance, “The NIST Definition of Cloud Computing,” NIST Information Technology Laboratory,
Computer Security Resource Center, SP 800-145, September 2011. https://csrc.nist.gov/publications/detail/sp/800-145/final.

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